Die holder



3 Sheets-Sheet l H. ALLEN DIE HOLDER Feb. 1, 1955 Filed Oct. 50, 1950INVENTOR.

Af/O/P/Vf Y5 HERBERT ALLEN Fig. I

Feb. 1, 1955 H. ALLEN 2,700,906

DIE HOLDER Filed Oct. 50, 1950 3 Sheets-Sheet 2 HERBERT ALLEN 2INVENTOR.

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Feb. 1, 1955 H. ALLEN 2,700,906

DIE HOLDER Filed Oct. 30, 1950 I5 Sheets-Sheet 5 HERBERT ALLEN INVENTOR.

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United States Patent DIE HOLDER Herbert Allen, Houston, Tex., assignorto Cameron Iron Works, Inc., Houston, Tex., a corporation of TexasApplication October 30, 1950, Serial No. 192,900

1 Claim. (CI. 78-60) This invention relates to improvements in dieholders and refers more particularly to die holders for forgingoperations with separable type dies.

In forging certain type of articles, it is necessary to use split diesin order that the dies may be separated to facilitate removal of theforging. In certain types of presses side rams are provided for holdingthe die halves together during a forging operation and the rams areretracted after the forging operation so that the die halves may beseparated. However, many presses do not have the side rams and a dieholder must be provided which will resist the forces which tend toseparate the split dies while the forging operation proceeds and whichwill permit ready separation of the dies to facilitate removal of thecompleted forging.

An object of this invention is to provide a die holder for split dieswherein the forces to which the die holding members are exposed during aforging operation are partially counterbalanced against each other so asto reduce the tendency of the dies to separate.

Another object is to provide a die holder with pivoted holding memberswherein the pivots are located relative to the die cavity so that theforces acting on the holding members due to a forging operation producetorques tending to rotate the members about their pivots which arelargely counterbalanced.

A further object is to provide a die holder having members which arepivoted for swin ing movement from a forging position to a separatedposition wherein the forces acting against the bottom of the die cavityproduce torque tending to swing the members in one direction and theforces acting laterally from the walls of the die produce forces actingagainst the members tending to rotate them in an opposite directionwhereby the resultant torque to which the members are exposed in aforging operation is not great.

Still another object is to provide a die holder of the characterdescribed wherein detent means may be provided for lockin the diemembers in forging position.

A still further object is to provide a die holder of the characterdescribed having knock out members to facilitate removal of finishedforgings.

Other and further objects of the invention will appear as thedescription proceeds.

In the accompanying drawings which form a part of the instantspecification and are to be read in conjunction therewith, and whereinlike reference numerals are used to indicate like parts in the variousviews:

Fig. l is a vertical sectional view illustrating die holding apparatusembodying this invention and showing fragmentary parts of a press;

Fig. 2 is a view similar to Fig. l but illustrates the holding apparatusin forging knock out position;

Fig. 3 is a top plan view partially in section of the apparatus shown inthe preceding figures; and

Fig. 4 is a view taken along the line 44 in Fig. 3 in the direction ofthe arrows.

The invention in general comprises a support to which are pivotallymounted holding members having recesses which in one position of themembers provide a die receiving cavity and in another position separatethe dies whereby forging may be readily released. The arrangement issuch that the members are freely swingable between these two operativepositions and the pivots for the members are so related to the diecavity that the forces acting against the die members produce verylittle, if any, resultant torque tending to rotate the die holdingcylinders.

2,700,906 Patented Feb. 1, 1955 lustrate the manner of use of the dieholder of this invention. The numeral 6 designates the bottom slide of apress and the knock out ram is shown at 7. At the uppe;l end of thedrawings there is shown at 8 the press punc The support means for thedie holder may be mounted upon an adapter plate 9 carried by the bottomslide and comprises a bottom member 10 with upright side parts 11secured along two sides of the bottom part by the plurality of capscrews 12. The holding members 13 are pivoted to the support means forswinging movement between the position of rest upon the bottom of thesupport means as shown in Fig. l, and an elevated knock out position asshown in Fig. 2.

The holding members are mounted upon the support means by hinge pins 14which extend between the side walls 11 and through apertures extendingtransversely of the holding members. In order to provide a large bearingsurface between the holding members and the side walls it is preferableto form these with trunnions. This may be accomplished by forming theside walls with cylindrical bearing parts 15 which fit in cylindricalrecesses 16 formed in the holding members. Actually the cylindricalmembers and recesses are approximately semicircular but do providecylindrical bearing surfaces upon which the holding members aresupported.

The holding members are provided with recessed portions 17 whichcooperate with the members in rest position to provide a die cavity inwhich the die parts 18 and 19 of a separable die may be disposed. Thebottom and wall surfaces of recesses 17 support the die parts which maybe secured therein by any suitable means as will be well understood bythose skilled in the art.

In order that the die holding members may be freely rotatable for knockout purposes but will not be rotated due to forces developed in forging,the pivots for the holding members are carefully positioned relative tothe die cavity so that the downward forces produce torques tending torotate the members in one direction and the lateral forces actingagainst the walls of the recesses 17 produce torque tending to rotatethe members in the opposing direction. By this means the resultanttorque may be controlled so as to be very small. Also the holdingmembers must be formed with cylindrical portions 20 which are struckupon a radius about the pivots or hinge pins centers 14. This permitsfree rotation of the holding members.

The hinge pins or pivots are preferably located relative to the cavityso that their centers reside in a horizontal plane about upon a levelwith the bottom of the die cavity. The surfaces 20 should extenddownwardly from this plane which includes the hinge pins centers.

With the die holder in accordance with this invention the forgingoperation may be carried out with substantially no resultant torquetending to cause the holding members to rotate in knock out position.However, when unusually high forgings are to be produced which requireextra long dies, the lateral forces acting against the walls of the diein a direction to rotate the holding members to open position areeffective against a-rather long moment arm. In order that the devicesmay be positively locked in forging position to avoid any possibility ofrotation of the members to open position, it is desirable to provide adetent means for securing the members in position of rest against thebottom of the support means.

This detent means may include cylinders 21 secured on each side of thesupport means, each one providing double Within the cylinders aremounted pistons 22 having pin extensions 23 extending throughregistering openings in the side walls of the support means and theholding members. These openings are designated at 24 and 25,respectively. Corresponding irregular surfaces 26 and 27 may be formedupon the openings 25 and pin 23, respectively, so that the pins will betightly wedged into locking position. To maintain these irregularsurfaces in proper alignment, guide pins 28 may project parallel to theaxis of the cylinders in which the pistons 22 are mounted. The pins 28extend through openings 29 in the pistons and inasmuch as these pins areoff center relative to the piston it maintains them in properorientation.

A suitable means may be provided for reciprocating the pistons andlocking pins. This means may include connections 30, 31 and 32, forsupplying power fluid, as for example compressed air, to the ends of thecylinders. Also, the same connections will exhaust spent power fluid anda suitable four-way valve may be employed for directing the power fluidand exhaust fluid to and from the cylinders. This four-way valve isshown schematically at 33 connected to lines 34 and 35 which may lead toa suitable source of power fluid and exhaust, respectively.

Means are provided for effectively swinging the holding members to openor knock out position and for simultaneously knocking the finishedforging from position within the dies. This means cooperates with theknock out ram 7 and includes a square opening 36 in the bottom member ofthe support means. The knock out ram may have a square head 37 whichfits within the opening 36 and this head engages the surfaces 38 and 39of the holding members to force them from their Fig. 1 to their Fig. 2position. The ram head 37 is provided with a rib 46 which engages theseats 47 to prevent rotation of the ram. Of course, the locking pins 23must be retracted in order to permit separation of the holding members.

The knock out means may be provided by pivoting knock out pins 40 and 41to the support, the pins extending through openings in the holdingmembers and registering openings in the die parts 18 and 19. The pivotfor the knock out pins preferably reside in slots formed in uprights 42and 43 secured to the bottom or base of the support means. Suitable capscrews are provided for securing the uprights in place. These uprightshave openings for receiving the hinge pins 14 and reside between yokearms 13a and 13b formed on the respective holding members. The yoke armsbetween the members are formed upon an inclined line 130 whereby the dieholders 13 may be rocked upon the hinge pins 14 without interference.This allows the holding members to be rotated to a Fig. 2 position. Fromthe Fig. 2 showing, it is apparent that the ends of the knock out pins40 and 41 engage the forging shown at 44 to knock it from the die as theholding members are retracted.

It is thought that the operation of the invention is apparent from theforegoing description. The die parts 18 and 19 are secured in theholding members, residing in the cavity provided by recesses 17. Themembers 13 are then moved to their Fig. 1 position and the four-wayvalve 33 manipulated to supply power fluid to move the detent means intolocking position. A suitable billet is then placed within the dies andthe usual blocking and extruding operations are carried out. In Fig. 1the finished forging is shown and it is obvious that because of theenlarged head at the lower end of the forging that it cannot be removedfrom the dies without separating them.

This removal is accomplished by manipulating four-way valve 33 so thatpower fluid enters the cylinders in back of pistons 22 through lines 30and 31. This retracts the locking pins and then knock out ram 7 is movedupwardly to force the holding members into Fig. 2 position.Simultaneously with the rocking of the holding members about theirpivots the knock out pins push the forging from the die parts so that itmay be readily removed.

During the actual forging operation the downward force which istransmitted from the punch 8 through the forging material and dies tothe holding members, tends to rotate them downwardly but this downwardrotation is resisted by the support bottom. The lateral forcestransmitted by the extruding metal to the walls of the die receivingcavity produce a torque about the pivots for the holding members whichtend to rotate the holding members toward open position. However, thepivot is so positioned relative to the cavity that the torque tending toopen the members is substantially counter-balanced by the torque tendingto rotate the members in the opposite direction. This is true becausethe pivots are located with their axes in a horizontal planesubstantially level with the bottom of the die receiving cavity. Thus,the moment arm for the downward forces or component of forces is verylong compared to the moment arm of the laterally acting forces. Wherethe forgings are to be made in extremely long dies, the effective momentarm for the laterally acting forces is somewhat lengthened and in orderto provide positively against any possibility of rotation of the holdingmembers toward open position, the detent means is provided. However,under any circumstances the resultant force or torque tending to openthe holding members will not be great so that no undue strain is placedupon the detent means.

It will be seen that the objects of this invention have beenaccomplished. There has been provided a die holding apparatus for usewith separable type forging dies upon presses which are not equippedwith side rams. The arrangement is such that high production rates maybe maintained. The construction is such that the downward forcesproduced in the forging operation counterbalance the laterally actingiorces which tend to separate the die parts. There has been provided dieholding apparatus which is rugged, economical, and of utility inmaintaining a high production rate in forging operations.

It Will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaim.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

A die holder for separable type forging dies comprising a support meansmade up of a bottom portion with upright side walls rigidly securedthereto; die holding members each pivoted by pivots to the upright sidewalls so as to be swingable upwardly therebetween from a position ofrest upon the support bottom portion; the die holding members havingrecesses which, with the die holding members in rest position, cooperateto provide a die receiving cavity; the pivots for said die holdingmembers being spaced upwardly from the support bottom portion; andknockout pins pivoted to the support means for upward swinging movementabout axes offset upwardly from the pivot axes of the die holdingmembers, said pins extending through openings in the die holding membersto facilitate removal of forgings.

References Cited in the file of this patent UNITED STATES PATENTS683,068 Prott Sept. 24, 1901 700,132 Brejcha May 13, 1902 1,204,127Canda Nov. 7, 1916 1,377,094 Root May 3, 1921 1,414,108 Becker et alApr. 25, 1922 1,464,434 Ljungstrom Aug. 7, 1923 2,541,544 Rahaim Feb.13, 1951 FOREIGN PATENTS 135,561 Austria Oct. 10, 1903 307,880 GermanySept. 14, 1918 661,471 Germany June 18, 1938

